1. Field of the Invention
The present invention relates to a heat-resistant, laminated conveyer belt and more particularly to a heat-resistant, laminated conveyer belt used in conveying all flat materials such as cardboard, resin made tile, and to its manufacturing method.
2. Description of the Related Art
In the past, as a conveyer belt used in conveying flat materials, e.g., paper and cardboard, there has been known a conveyer belt in which two to six belts base materials of the same type are laminated through a PFA fluorocarbon resin film, and the conveyer belt made up of two or more layers of belt base materials has been used according to the strength required for its application.
FIG. 4 shows a conventional conveyer belt. This conveyer belt is formed by sandwiching a PFA fluorocarbon resin film 43 between heat-resistant fiber cloths 41 and 42. The heat-resistant fiber cloths are woven cloths made of glass fiber, carbon fiber, aramid fiber and aromatic allylate fiber, and they are also woven in the form of plain weave, satin weave and twill weave. Moreover, the heat-resistant cloth is impregnated on, at least, one side of the surface with TFE fluorocarbon resin, dried, and sintered, and it follows that this composite possesses exceptional properties, that is, high chemical resistance, heat resistance, anti-stick property, and wear resistance. Furthermore, in some cases, an one-layer belt is used under high tension. However, normally, the conveyer belt, which is made up of two or more layers, is used.
However, when two above-mentioned fluoroplastic composites with the heat-resistant cloths of the sameweave are thermally pressurized, thereby obtaining a two-layer belt, the upper layer (hereinafter called "the wear-resistant layer") cannot follow the expansion and contraction of the lower layer (hereinafter called "the reinforcing layer") because of the difference in the circumferential length between the wear-resistant layer and the reinforcing layer. As a result, a surface separation occurs between the heat-resistant fiber cloths and the impregnated fluoroplastic layer inside the wear-resistant layer by the shearing stress of the surface between the reinforcing layer and the wear-resistant layer and/or the shearing stress of the wear-resistant layer itself. Due to this, there is a problem in that the original properties of fluoroplastic are lost and the lifetime of the belt is shortened.